Wood construction has been utilized for thousands of years to create structures and various different infrastructures. From Biblical times wood has been used to make boats such as Noah's Ark to currently where whole buildings are being constructed. Before anyone started paying attention to how renewable a resource was, people realized wood was quite readily available. Only until quite recently has there been thought given to the sustainability of wood construction. Even with these thoughts being quite recent, there have been significant advances in the sustainability of wood construction over the course of time. Before attempting to investigate any further into what these advances are, it is important to understand the meaning of sustainability: meeting the needs of the present without compromising the ability of future generations to meet their needs. Moving forward, the sustainability of wood construction has advanced because wood is the only material available that grows naturally, is renewable, and significantly reduces the carbon footprint left from a construction project.
Background and Improvement in Sustainability
As one of the oldest construction materials, wood has made an important impact on world exploration and trade mostly used by merchant ships and navies. Wood was also commonly used with railway engineering and construction. However, in some instances wood has been replaced by other materials such as steel and concrete.[1]
Wooden Sail Boat
Wood construction can be considered environmentally friendly in that it is a renewable resource; however, some methods used to make wood a more suitable resource for construction come at the cost of making it harmful to the environment. One example of this is wood treatment chemicals. Chemicals are used to treat the wood to prevent rotting, as well as insect damage. An example of a chemical that is used to treat wood is chromated copper arsenate (CCA). This chemical has been used to treat lumber since the 1940’s. The majority of wood used in outdoor residential settings since the 1970’s has been wood treated with CCA. Since the pesticide contains arsenic, it can be hazardous to people. For this reason, the EPA completed a reregistration eligibility decision (RED) to determine that this chemical cannot be used to treat wood that will be used in residential construction (with certain exceptions). Some arsenic-free alternatives to CCA are borates, copper azole, cyproconazole, propiconazole, and alkaline copper quaternary (ACQ).[2]
The creation of the Forest Stewardship council also helped to make wood a more sustainable material. This group of businesses, environmentalists, and community leaders formed after the 1992 Earth Summit in Rio failed to make an agreement to stop deforestation. Their first meeting was in 1993 in Toronto, Canada, where they set out to create a voluntary, market-based approach to improve forest practices throughout the world. They currently operate in more than 80 countries, where forests are present. This group attempts to control deforestation to help keep the tree population alive and thriving, which, in turn, keeps the wood supply sustainable. This along with planting and maintaining actual tree farms helps to keep a healthy supply of trees to use in construction.[3]
Financial Considerations
Wood is a relatively cheap construction material because it is currently so plentiful. There are, however,
Redwood Trees
important financial decisions that need to be made when considering using wood as a construction material. It is important to look at what type of wood, as well as what type of treatment, should be used in a certain project. In order to construct a building that will last a long time, it should be decided early on what project is being approached because based on that decision one has to decide whether hard wood or soft wood would be feasible for the project, what chemicals are needed to protect the wood from water and insects, and what chemicals are safe to use. A significant part of determining these things is to make sure the focus remains on not only what is cheapest, but what is safest.
Not every business uses rating systems like LEED when constructing buildings
Applications
Wood is more eco-friendly in that it reduces the carbon footprint by slowing the process of a tree emitting carbon into the atmosphere. This causes wood construction to be more sustainable because people will be encouraged to use it more so than steel or concrete due to its benefits of being more environmentally friendly. One example of this is the Arena Stage in Washington, D.C. This structure stores about 215 metric tons of carbon dioxide which is the equivalent of removing 129 cars from the road for a year. The U.S. Environmental Protection Agency (EPA) estimates that up to 1.1 tons of carbon dioxide is produced for every ton of cement that is produced.[6] Comparing the amount of wood used to the amount of concrete that could be used in its place, a conclusion can be drawn that wood is the more environmentally friendly option, and therefore, more sustainable.
LEED, or Leadership in Energy and Environmental Design, is another example of a factor that aids in advancing sustainability of wood construction. Rating systems like LEED also help improve sustainability of wooden structures. This system rates the design, construction, operation, and maintenance for green buildings, homes, and neighborhoods to aid in maintaining proper environmentally friendly construction methods. LEED certification is earned through satisfying prerequisites and earning points to achieve certain levels of certification. Each rating system has its own prerequisites and credits, and teams choose which is best for their project.
Research on Wood Sustainability
Seven principles of sustainable construction are: reduce resource consumption, reuse resources, use recyclables, protect nature, eliminate toxins, apply economics, and focus on quality.[7] This means careful attention should be placed on the usage of wood as a construction material. It is important to keep forests well maintained so that they can remain a renewable resource. If all the forests die off, there will be no more wood to use for construction. Half of all major industrial raw materials used in the United States come from forests, which means forest health is significant.[8] If wood is to advance more in its sustainability as a construction material, deforestation needs to be kept under control along with the planting of trees as they are cut down. Another significant factor in keeping wood materials sustainable is preventing decay. The primary cause of wood decay in structures is contact with water, which leads to the growth of fungi on the wood. Wood can come in contact with water in 5 ways: through the original water in green wood, rainwater, ground water, condensation, or plumbing leaks. In this area of the United States, hot and humid weather is common, which means special precautions need to be taken when using wood to construct buildings. Termites, the Formosan termite in particular, and wood decay fungi are considered a major challenge in keeping wood a sustainable material in the southern US. [9] They coexist interdependently and cause damage to all types of wooden structures in hot-humid climates.
The usage of screw and bolt connections rather than glue and nails makes the wooden structure more sustainable, also. This is because fasteners made of stainless steel or mild steel coated with zinc/zinc-cadmium resists corrosion, allowing the structure to hold up longer.[10]
Click the links below for further research on the topic:
Lewis, David C and Kitchens, Shane C. (2006). "Sustainable House for the Southeastern United States." Mississippi State University, <www.fwrc.msstate.edu/housing/images/sustainable.pdf>. (December 2, 2015).
Background and Improvement in Sustainability
As one of the oldest construction materials, wood has made an important impact on world exploration and trade mostly used by merchant ships and navies. Wood was also commonly used with railway engineering and construction. However, in some instances wood has been replaced by other materials such as steel and concrete.[1]
Wood construction can be considered environmentally friendly in that it is a renewable resource; however, some methods used to make wood a more suitable resource for construction come at the cost of making it harmful to the environment. One example of this is wood treatment chemicals. Chemicals are used to treat the wood to prevent rotting, as well as insect damage. An example of a chemical that is used to treat wood is chromated copper arsenate (CCA). This chemical has been used to treat lumber since the 1940’s. The majority of wood used in outdoor residential settings since the 1970’s has been wood treated with CCA. Since the pesticide contains arsenic, it can be hazardous to people. For this reason, the EPA completed a reregistration eligibility decision (RED) to determine that this chemical cannot be used to treat wood that will be used in residential construction (with certain exceptions). Some arsenic-free alternatives to CCA are borates, copper azole, cyproconazole, propiconazole, and alkaline copp
The creation of the Forest Stewardship council also helped to make wood a more sustainable material. This group of businesses, environmentalists, and community leaders formed after the 1992 Earth Summit in Rio failed to make an agreement to stop deforestation. Their first meeting was in 1993 in Toronto, Canada, where they set out to create a voluntary, market-based approach to improve forest practices throughout the world. They currently operate in more than 80 countries, where forests are present. This group attempts to control deforestation to help keep the tree population alive and thriving, which, in turn, keeps the wood supply sustainable. This along with planting and maintaining actual tree farms helps to keep a healthy supply of trees to use in construction.[3]
Financial Considerations
Wood is a relatively cheap construction material because it is currently so plentiful. There are, however,
made when considering using wood as a construction material. It is important to look at what type of wood, as well as what type of treatment, should be used in a certain project. In order to construct a building that will last a long time, it should be decided early on what project is being approached because based on that decision one has to decide whether hard wood or soft wood would be feasible for the project, what chemicals are needed to protect the wood from water and insects, and what chemicals are safe to use. A significant part of determining these things is to make sure the focus remains on not only what is cheapest, but what is safest.
Advantages and Disadvantages
Advantages[4]
- There will be a sustainable supply of wood as long as harvesting of lumber and timber is kept under control
- Wood can be treated with chemicals so that it will last longer
- Wood has a long-term performance and durability
- Wood is relatively cheap compared to other methods of construction because trees are so plentiful
- Easy scheduling and speed of construction is faster than other materials
- Wood has natural insulating properties
Disadvantages[5]Applications
Wood is more eco-friendly in that it reduces the carbon footprint by slowing the process of a tree emitting carbon into the atmosphere. This causes wood construction to be more sustainable because people will be encouraged to use it more so than steel or concrete due to its benefits of being more environmentally friendly. One example of this is the Arena Stage in Washington, D.C. This structure stores about 215 metric tons of carbon dioxide which is the equivalent of removing 129 cars from the road for a year. The U.S. Environmental Protection Agency (EPA) estimates that up to 1.1 tons of carbon dioxide is produced for every ton of cement that is produced.[6] Comparing the amount of wood used to the amount of concrete that could be used in its place, a conclusion can be drawn that wood is the more environmentally friendly option, and therefore, more sustainable.
LEED, or Leadership in Energy and Environmental Design, is another example of a factor that aids in advancing sustainability of wood construction. Rating systems like LEED also help improve sustainability of wooden structures. This system rates the design, construction, operation, and maintenance for green buildings, homes, and neighborhoods to aid in maintaining proper environmentally friendly construction methods. LEED certification is earned through satisfying prerequisites and earning points to achieve certain levels of certification. Each rating system has its own prerequisites and credits, and teams choose which is best for their project.
Research on Wood Sustainability
Seven principles of sustainable construction are: reduce resource consumption, reuse resources, use recyclables, protect nature, eliminate toxins, apply economics, and focus on quality.[7]
This means careful attention should be placed on the usage of wood as a construction material. It is important to keep forests well maintained so that they can remain a renewable resource. If all the forests die off, there will be no more wood to use for construction. Half of all major industrial raw materials used in the United States come from forests, which means forest health is significant.[8] If wood is to advance more in its sustainability as a construction material, deforestation needs to be kept under control along with the planting of trees as they are cut down.
Another significant factor in keeping wood materials sustainable is preventing decay. The primary cause of wood decay in structures is contact with water, which leads to the growth of fungi on the wood. Wood can come in contact with water in 5 ways: through the original water in green wood, rainwater, ground water, condensation, or plumbing leaks. In this area of the United States, hot and humid weather is common, which means special precautions need to be taken when using wood to construct buildings. Termites, the Formosan termite in particular, and wood decay fungi are considered a major challenge in keeping wood a sustainable material in the southern US. [9] They coexist interdependently and cause damage to all types of wooden structures in hot-humid climates.
The usage of screw and bolt connections rather than glue and nails makes the wooden structure more sustainable, also. This is because fasteners made of stainless steel or mild steel coated with zinc/zinc-cadmium resists corrosion, allowing the structure to hold up longer.[10]
Click the links below for further research on the topic:
http://www.usda.gov/wps/portal/usda/usdamediafb?contentid=2011/09/0426.xml&printable=true&contentidonly=true
http://www.usgbc.org/leed
Shreir, L.L., and Jarman, R.A., and Burstein, G.T. (1994)." Corrosion." (3rd Edition) Volumes 1-2. Elsevier,<http://app.knovel.com/hotlink/toc/id:kpCEV00003/corrosion-3rd-edition>(Dec. 2, 2015).
Yudelson, J. and Despang, M. (2013). "Rethinking Wood as a Sustainable Material." Construction Executive, <http://www.constructionexec.com/Issues/June_2013/Special_Section4.aspx> (December 2, 2015).
Wormell, Lance. (2015). "Chromated Copper Arsenate." US Environmental Protection Agency,
<http://www.epa.gov/oppad001/reregistration/cca/> (December 2, 2015).
(2014). "LEED." US Green Building Council. <http://www.usgbc.org/leed> (December 2, 2015).
Shreir, L.L., and Jarman, R.A., and Burstein, G.T. (1994)." Corrosion." (3rd Edition) Volumes 1-2. Elsevier,<http://app.knovel.com/hotlink/toc/id:kpCEV00003/corrosion-3rd-edition> (December 2, 2015).
Yudelson, J. and Despang, M. (2013). "Rethinking Wood as a Sustainable Material." Construction Executive, <http://www.constructionexec.com/Issues/June_2013/Special_Section4.aspx> (Dec. 2, 2015).
Campbell, Brandon S. (2013). "Sustainable Workflows for Permanent Modular Wood Construction." Brandon S. Campbell. <http://webcache.googleusercontent.com/search?q=cache:hjNOVXJCwAEJ:https://soa.utexas.edu/file/1348/download+&cd=3&hl=en&ct=clnk&gl=us>. (December 2, 2015).
Falk, Robert H. "Wood as a Sustainable Building Material." <www.fpl.fs.fed.us/documnts/fplgtr/fplgtr190/chapter_01.pdf >. (December 2, 2015).
Lewis, David C and Kitchens, Shane C. (2006). "Sustainable House for the Southeastern United States." Mississippi State University, <www.fwrc.msstate.edu/housing/images/sustainable.pdf>. (December 2, 2015).
Hansen, Gail. (2013). "Sustainable Landscape Construction: Materials and Products - Wood." University of Florida. <http://edis.ifas.ufl.edu/ep403>. (December 2, 2015).